This Application claims the benefit of U.S. Provisional application Ser. No. 60/037,129, filed Feb. 4, 1997.
Herbicidal sulfamoyl urea compounds are described in WO 95/29902, EP 661,276, WO 95/29167 and U.S. Pat. No. 4,622,065. A particularly potent and highly cereal selective sulfamoyl urea herbicidal agent is the subject of U.S. Pat. No. 5,009,699. This agent is especially useful for the selective control of a variety of weed species in the presence of cereal crops and particularly for controlling broadleaf weeds and sedges in the presence of transplanted or paddy rice. Therefore, alternate, effective, cost-efficient methods of manufacture of herbicidal sulfamoyl ureas, and particularly cereal-selective sulfamoyl ureas, are of continued interest.
Certain key intermediates in the manufacture of the above-said herbicides and the cereal-selective herbicide, 1-{o-(cyclopropylcarbonyl)phenyl!sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidiny l)urea, such as o-aminophenyl cyclopropyl ketone, o-nitrophenyl cyclopropyl ketone, 4-halo-o-nitrobutyrophenone, and 4-halo-o-aminobutyrophenone are described in U.S. Pat. Nos. 5,362,911; 5,364,968; 5,405,998 and 5,414,136. However, alternate and effective methods to prepare these key intermediate alkyl and cycloalkyl phenyl ketones and their derivatives from readily available, non-toxic starting materials are still being sought.
Therefore, it is an object of this invention to provide aryne compounds useful to prepare substituted and unsubstituted 4-hydroxy-(o-substituted phenyl)butyrophenone intermediate compounds.
It is another object of this invention to provide a process to prepare said aryne compounds from readily available, relatively non-toxic starting materials.
It is a further object of this invention to provide an alternate process for the manufacture of key intermediates useful in the manufacture of sulfamoyl urea herbicidal agents and sulfamoyl urea, cereal-selective, herbicidal agents.
It is a feature of this invention that the preparative methods allow for the use of readily available, relatively non-toxic and cost-efficient starting materials.
Other objects and features of the invention will become apparent from the detailed description thereof set forth hereinbelow.